• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.5
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• pp.504-510
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• 2018

Marine casualties are caused mainly by collisions and grounding, due to human error. The SMART Navigation Service is preparing a measure to reduce marine casualties caused by human error and establish an LTE Accident Vulnerability Monitoring System (SV10) to evaluate the danger of collision or grounding for a vessel based on location information collected on land. This service will also share real-time vessel locations and danger information with related agencies to enable them to respond more quickly to accidents on land. In this study, statistical reports on marine casualties and investigation reports provided by the Korea Maritime Safety Tribunal are analyzed, so the percentage of marine casualties that could be reduced using the SV10 service could be identified.

• Journal of Navigation and Port Research
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• v.38 no.1
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• pp.53-57
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• 2014

This thesis, concentrates on marine collision risks of the area divided by cells. Using a gas molecular collision calculation model, a collision risk model is proposed. Collision risk is estimated by relative angle, relative speed, and ship's density in the cell. For one week, Automatic Identification System (AIS) data was collected and analyzed on the Busan North Port area. The results indicate a high-risk area at the sea route connection point in Busan North Port. It also shows that twilight is the time of day when most collisions occur. This means that the area is high risk due to the number of collisions and other dangerous factors related to twilight. Although there is still need to consider other risks such as grounding risks, the results of this study are useful to for plotting a risk map for the port.

• Journal of Ocean Engineering and Technology
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• v.23 no.1
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• pp.81-88
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• 2009

An evaluation of the structural integrity of an oceanographic buoy subjected to extreme loads was carried out in this study. Load components, such as the current, waves, and wind load, which were required for the sea's environmental conditions, were calculated precisely. A non linear finite element analysis was conducted to elucidate the structural response of the buoy under extreme environmental conditions. Based on the surface drift velocity scheme, a dynamic impact analysis was also carried out for the case of collision accidents. The proposed numerical technique would be a useful and cost effective tool for design scheme evaluation in the field of oceanographic buoys.

• Journal of Navigation and Port Research
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• v.36 no.9
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• pp.721-728
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• 2012

Marine traffic safety of the Vung Tau Waterway, from port limit to Ganh Rai Gulf, plays a crucial role in the economic development of the important triangular economic zone in the south of Vietnam: Ho Chi Minh City, Dong Nai Province, Ba Ria-Vung Tau Province. This paper uses the IWRAP Mk2 program to assess marine traffic safety and shows that in the area there are three parts of fairway have highest risk of collision (from buoys No. 8-9 to buoys No. 1-2 of the Song Dinh fairway; from buoy No. 0 to buoys No. 8-9 and from buoys No. 6-9 to buoys No. 8-9A of the Sai Gon-Vung Tau fairway) and the two areas have highest risk of grounding (the Vung Tau coastline from Ganh Hao to Sao Mai and an area in the Ganh Rai Gulf). In addition, the result of a questionnaire survey on a group of Pilots shows that wind, current and rain/fog have considerable negative effect to ship handling of large vessels in this area. This paper's results will be used in the further research to discover solutions for improving marine traffic safety in the Vung Tau Waterway.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.3B
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• pp.248-253
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• 2011

Collision avoidance algorithm of vessels have been studied to avoid collision and grounding of a vessel due to human error. In this paper, We propose a collision avoidance algorithm using bayesian estimation theory for safety sailing and reduced risk of collision accident. We calculate collision risk for efficient collision avoidance using bayesian algorithm and determined the safest and most effective collision risk is predicted by using re-planned with re-evaluated collision risk in the future(t=t'). Others ship position is assumed to be informed from AIS. Experimental results show that we estimate the safest and most effective collision risk.

• Journal of the Society of Naval Architects of Korea
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• v.46 no.6
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• pp.611-621
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• 2009

This paper first reviews the physical meanings and the expressions of two representative strain rate models: CSM (Cowper-Symonds Model) and JCM (Johnson-Cook Model). Since it is known that the CSM and the JCM are suitable for low-intermediate and intermediate-high rate ranges, many studies regarding marine accidents such as ship collision/grounding and explosion in FPSO have employed the CSM. A formula to predict the material constant of the CSM is introduced from literature survey. Numerical simulations with two different material constitutive equations, classical metal plasticity model based on von Mises yield function and micromechanical porous plasticity model based on Gurson yield function, have been carried out for the stiffened plates under impact loading. Simulation results coincide with experimental results better when using the porous plasticity model.

• Journal of the Korean Association of Geographic Information Studies
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• v.21 no.1
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• pp.83-95
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• 2018

With recent technological advances in the shipbuilding industry, vessels have been improved in size and performance. As a result, an accident such as grounding, caused by a single ship-to-ship collision, could lead to a large-scale maritime disaster. Considering the seriousness of the situation, the international community has been consistently updating the standards for Electronic Navigational Chart(ENC) to improve the maritime safety. S-57, the existing ENC standard governed by the International Hydrographic Organization(IHO), includes standards for generating conventional binary-type ENC data sets. The S-57 standard, however, has not been updated since the release of Version 3.1 in December 2000. Since then, the standard has failed to reflect technological development regarding maritime spacial information, which has been consistently improving. In an effort to address this concern, the IHO designated S-100, i.e., the next-generation ENC production standard. S-100 differs from S-57 in data exchange type. Contrary to the conventional ENC standards, which use binary-type data, S-10X, based on the next-generation ENC standards, uses ENC data composed of Feature Catalogue, Portrayal Catalogue, and GML. Considering this fact, it is necessary to update S-58, the ENC validation check standard, or designate a new standard for ENC validation checks. This study is developed own software to implement validation checks for new types of data, and identified improvement points based on the test results.

• Journal of Navigation and Port Research
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• v.40 no.6
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• pp.391-400
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• 2016

A number of maritime accidents, and accident response activities, including the command and control procedures that were implemented at accident scenes, are analyzed to derive useful information about responding to maritime accidents, and to understand how the chain of events developed after the initial accident. In this research, a new concept of a 'risk based accident response support system' is proposed. In order to identify the event chains and associated hazards related to the accident response activities, this study proposes a 'Brainstorming technique for scenario identification', based on the concept of the HAZID technique. A modified version of Event Tree Analysis was used for quantitative risk analysis of maritime accident response activities. PERT/CPM was used to analyze accident response activities and for calculating overall (expected) response activity completion time. Also, the risk based accident response support system proposed in this paper is explained using a simple case study of risk analysis for oil tanker grounding accident response.

• Journal of Ocean Engineering and Technology
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• v.25 no.2
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• pp.134-144
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• 2011

In this paper, the global study trends for material behaviors are investigated regarding the static and dynamic hardenings and final fractures of marine structural steels. In particular, after reviewing all of the papers published at the 4th and 5th ICCGS (International Conference on Collision and Grounding of Ship), the used hardening and fracture properties are summarized, explicitly presenting the material properties. Although some studies have attempted to employ new plasticity and fracture models, it is obvious that most still employed an ideal hardening rule such as perfect plastic or linear hardening and a simple shear fracture criterion with an assumed value of failure strain. HSE (2001) presented pioneering study results regarding the temperature dependency of material strain hardening at various levels of temperature, but did not show strain rate hardening at intermediate or high strain rate ranges. Nemat-Nasser and Guo (2003) carried out fully coupled tests for DH-36 steel: strain hardening, strain rate hardening, and temperature hardening and softening at multiple steps of strain rates and temperatures. The main goal of this paper is to provide the theoretical background for strain and strain rate hardening. In addition, it presents the procedure and methodology needed to derive the material constants for the static hardening constitutive equations of Ludwik, Hollomon, Swift, and Ramberg-Osgood and for the dynamic hardening constitutive equations of power from Cowper-Symonds and Johnson-Cook.

• Journal of the Society of Naval Architects of Korea
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• v.32 no.3
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• pp.107-115
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• 1995

A simple estimation system of ultimate and residual strength for ship structures is developed on the Open-Window system of SUN4 engineering workstation. System development consists of three stages. Firstly, various ultimate longitudinal strength estimation methods are investigated and some rational estimation methods are adopted based on the parametric comparison of various hulls or box girders. Secondly, these selected and newly formulated methods are linked with elastic & perfectly plastic section modulus calculation procedure. Therefore, the longitudinal hull girder strength can be calculated in the intact and damaged conditions due to the grounding or collision of hull structure. Finally, an exclusive system is developed such that whole procedures are proceeded under the window management system using mouse button and elastic and perfect plastic stress conditions. Also longitudinal members are plotted automatically under three dimensional graphic circumstances. These established program is tested for various actual ships, and some examples are illustrated.